Family Finder – Family Matching System

Family Tree DNA has recently released Family Matching, an enhancement for our Family Finder customers.

The Family Matching feature assigns maternal or paternal icons to a customer’s match list based on phased matching to close relatives in conjunction with a special Family Matching threshold.In order to take advantage of this feature, a user must have a tree uploaded or created in their Family Tree DNA account, and the DNA kits of relatives must be linked to the appropriate individual in the user’s tree.

The Family Matching feature allows you to view your confirmed maternal and paternal matches at a glance when relatives from that side of your tree have tested with Family Tree DNA.

The Family Matching tool is not limited to Parents and uses anyone currently linked to your tree between Parent to 3rd cousin.

We plan to continue working on Family Matching and adding more distant relations.

Family Matching continues to populate information when linking more matches beyond a linked immediate parental relationship range. We always recommend linking all members of your family, even if a particular relationship is not currently in use, as it may be in the future.

Relationships are validated based on Family Finder’s range with a +- formula depending upon the distance. For example, the system will not use someone as a parent if they are calculated as a 2nd cousin.

Family Matching does not populate based on relationships indicated by users in the “Known Relationship” field, but rather assigns maternal and paternal icons only based on single or multiple linked kits, the phased matching algorithm and the Family Matching threshold.

The Family Matching system is not based on the In-Common With/Not-In-Common With feature which is entirely based on the match list. Instead, Family Matching is based on phased blocks detected between relations, taking into account phased information is significant as it ensures that the block is not only of similar size and in the same location, but also transmitted by the same alleles.

While the matching is done using a variety of formulas based on phased DNA, there is currently one threshold that is hard-coded.The current version of the Family Matching system takes into account only those blocks that are equal to or longer than 9cM. As we acquire more data, this number over time is likely to change and become lower.

Due to several reasons, including the hard-coded 9cm threshold, many matches will show up on an individual’s match page yet do not include the maternal or paternal icon.These matches may still be valid, but have not yet been assigned based on the phased Family Matching criteria today.

On average with our current formulas, roughly 30-50% of matches (as long as both parents or neither parent comes from an endogamic population) are bucketed with at least one linked node of a parent.Additionally, we are seeing between 10 and 20% of matches bucketed with at least one linked node of an Aunt/Niece or Uncle/Nephew to 1st Cousin.

As more people link nodes, we expect to release a new version that will allow the incorporation of those additionally linked nodes on their trees. All users will be automatically upgraded.

We have plans for forthcoming upgrades, as this is merely the first in a long line of enhancements designed and projected for the near future.

The number of users has been greater than expected with our soft launch of this latest feature. We are currently working on both speed and additional upgrades which will improve the current experience and help with future enhancements and new features. The first planned update is expected within the next six weeks. Further details on new enhancements to the Family Matching system will be released as we get closer to the launch and refine all the newest features.